Inactivity Timer in a Discontinuous Reception Configured System

ABSTRACT

Systems, methods and wireless devices are provided that utilize a timer to ensure a receiver of a wireless device is on to receive downlink transmissions. In the event the timer runs out without further resource allocation, the mobile device turns its radio off. If a further resource allocation occurs while the timer is running, the timer is restarted.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 60/956,845 filed on Aug. 20, 2007, and U.S. Provisional ApplicationSer. No. 60/974,653 filed on Sep. 24, 2007 which are incorporated hereinby reference in their entirety.

FIELD OF THE APPLICATION

The application relates to wireless communication, and more particularlyto transmission scheduling for wireless communication.

BACKGROUND

With semi-persistent scheduling, for downlink VoIP (voice over IP(Internet Protocol)) communications to a mobile device, a periodic DL(downlink) transmission resource is allocated during a talk-spurt on thedownlink. The same resource is allocated each time. The allocation isturned on during each of the talk-spurts and off between talk-spurts. Inthis manner, explicit signalling to request an allocation, and to granta particular VoIP allocation is not required. Semi-persistent schedulingfor uplink VoIP communications from a mobile station is similar.

In addition to regular VoIP traffic, mobile devices also need theability to send and transmit larger IP packets. Such larger IP packetsare likely to be relatively infrequent compared to the frequency ofregular VoIP transmissions. Such packets might include uncompressed IPpackets, RTCP (Remote Transmit Power Control) packets, SIP/SDP (SessionInitiation Protocol/Session Description Protocol) packets, etc. Such IPpackets may be several hundreds of bytes in size and may have highpriority. In addition, larger packets may be required to transmit RRC(Radio Resource Control) Signalling messages. Examples of this arehandover related messages such as measurement reports. Some mobiledevices will also need the ability to deliver a mixed service in whichcase services in addition to VoIP need to be provided to the mobiledevice, such as e-mail, web browsing etc.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described with reference to the attacheddrawings in which:

FIG. 1 is a signalling diagram showing dynamic scheduling vs.semi-persistent scheduling;

FIG. 2 is a block diagram of an example wireless system;

FIG. 3 is a signalling diagram showing an awake period for dynamicscheduling in DRX (discontinuous reception);

FIG. 4 is a signalling diagram showing DRX and DTX (discontinuoustransmission) for uplink and downlink;

FIG. 5 is a state diagram having DRX and DTX transitions for VoIP;

FIGS. 6 and 7 are flowcharts of methods executed by a network to performcombined semi-persistent and dynamic scheduling;

FIG. 8 and 9 are flowcharts of methods executed by a mobile device toperform combined semi-persistent and dynamic scheduling;

FIG. 10 is a block diagram of a mobile device;

FIG. 11 is a flowchart of a method in a mobile device to keep its radioon to allow for dynamic allocations; and

FIG. 12 is a flowchart of a method in a wireless network for sendingdynamic allocations to a mobile device.

DETAILED DESCRIPTION OF EMBODIMENTS

According to one broad aspect, the application provides a method in awireless device, the method comprising: configuring the device fordiscontinuous reception (DRX) having on durations; receiving signallingover a control channel, during one of the on durations; and starting aninactivity timer.

According to another broad aspect, the application provides a wirelessdevice comprising: a processor configured to control a receiver to haveon durations; a receiver configured to receive signalling over a controlchannel during one of the on durations; and the processor furtherconfigured to start an inactivity timer upon reception of the signallingover the control channel.

According to another broad aspect, the application provides a method ofcontrolling a radio in a wireless device, the method comprising:controlling the radio during a plurality of awake periods and aplurality of sleep periods, the awake periods alternating in time withthe sleep periods, such that the radio is always on during each of theawake periods, and the radio is off for at least some of the sleepperiods; receiving, during one of the awake periods, signaling thatdefines a downlink transmission resource to communicate a packet orsub-packet, the transmission resource allocated during a portion of asleep period; controlling the radio to be on during the portion of thesleep period; and monitoring, during the portion of the sleep period,for signaling that defines an additional transmission resource tocommunicate an additional downlink packet or sub-packet, and in theevent such signaling is received, controlling the radio to be on for anadditional portion of a sleep period.

According to another broad aspect, the application provides a wirelessdevice comprising: a wireless access radio for sending and receivingwireless communications to and from a network; a radio manager thatcontrols the radio of the wireless device during a plurality of awakeperiods and a plurality of sleep periods, the awake periods alternatingin time with the sleep periods, such that the radio is always on duringeach of the awake periods, and the radio is off for at least some of thesleep periods; the wireless device further configured to: receive,during one of the awake periods, signaling that defines a downlinktransmission resource to transmit an additional downlink packet orsub-packet, the downlink transmission resource allocated during aportion of a sleep period; control the radio to be on during the portionof the sleep period; and monitor, during the portion of the sleepperiod, for signalling that defines additional downlink transmissionresource to transmit another additional downlink packet or sub-packet,and in the event such signalling is received, controlling the radio tobe on for an additional portion of a sleep period.

Further aspects provide wireless networks, base stations, wirelessdevices that execute one or more of the methods summarized above ordetailed herein. Another embodiment provides a computer readable mediumhaving computer readable instructions for controlling the execution ofone or more of the methods summarized above or detailed herein.

Dynamic scheduling has been proposed to allow the dynamic allocation oftransmission resources, and the subsequent transmission of a largepacket using the dynamically allocated resources. Dynamic schedulinginvolves allocating a resource each time a packet is to be transmitted,and the resource can differ for each allocation. In a particularexample, see Applicant's co-pending U.S. Provisional Patent ApplicationNo. 60/944,376 filed on Jun. 15, 2007 and hereby incorporated byreference in its entirety.

In a specific example, a mobile device supporting VoIP with dynamicscheduling monitors layer 1 CCEs (Control Channel Elements) continuouslyfor dynamic scheduling grants even though the mobile device might beonly involved in a VoIP session. LTE (Long Term Evolution) refers toCCEs, but the term has more general application to mean simply controlinformation.

As indicated above, a mobile device may support VoIP with dynamicscheduling by monitoring layer 1 CCEs continuously for dynamicscheduling grants. Unfortunately, this might waste battery power for themobile device, particularly when there are very few or even no dynamicscheduling grants for the mobile device.

Referring now to FIG. 1, shown is a signalling diagram showing dynamicscheduling vs. semi-persistent scheduling. Time is on the horizontalaxis. Shown is a periodic semi-persistent allocation 50. For VoIPtransmission, this can for example include a resource allocated every 20ms. In addition, there is a regular set of layer 1 CCEs 52 that aretransmitted. In the illustrated example, these are transmitted in every1 ms but it is to be clearly understood that the other resourceallocation periods and CCE periods are possible. This example assumesdownlink transmission, but a similar approach applies to uplinktransmission. During the periods that occur between talk-spurts, (alsoreferred to as “silence” or “silence periods”), the transmitter andreceiver can be turned off. During a talk-spurt period (also referred toas a period that VoIP transmission is “active”, or “active mode”), ifnot for dynamic scheduling, the mobile device could wake up regularly toblind-detect its data in the semi-persistently allocated resource at thepre-defined interval (e.g. every 20 ms) while entering a “sleeping” modeat other times. This can also be referred to as DRX (discontinuousreception). This simply means that the receive capability of the mobiledevice's radio is basically turned off while the mobile device is insleep mode thereby resulting in battery life extension. However, giventhat other data may arrive via dynamic scheduling by any of the CCEs 52,the mobile device needs to monitor the CCEs of all sub-frames. In thefull dynamic scheduling case there is no DTX or DRX ruling out thepossibility of using DRX since the mobile device needs to continuemonitoring the layer 1 CCEs for dynamic scheduling grants for possibledata coming. This is not power efficient and leads to lower batterycharge lifetimes.

To efficiently support the DRX in VoIP active mode in order to reducethe battery power consumption, systems and methods are provided forcombining semi-persistent scheduling for VoIP with a schedulingcapability for additional packet transmission. These methods areparticularly effective for a mobile device that is only involved in aVoIP session (i.e. not requiring mixed service).

System for Semi-Persistent Scheduling and DRX Control

Referring now to FIG. 2, shown is a block diagram of an example wirelesssystem 40. The wireless system 40 has a wireless network 28 and a mobiledevice 10. The wireless system also has other mobile devices 30.

The mobile device 10 has a wireless access radio 12, a processor 16 anda radio manager 14 that is responsible for controlling the wirelessaccess radio 12. There may be additional components not shown. Thewireless network 28 has a scheduler 32 that encompasses asemi-persistent scheduler 34 and a dynamic scheduler 36. The scheduler32 may reside in a base station or elsewhere in the network 28. In LTE,the scheduler is typically in the eNB (enhanced NodeB). In the examplesthat follow, it is assumed that scheduler 32, transceiver 31 and antenna33 are all parts of a base station. Also shown is a DRX controller 29that is responsible for setting up/configuring/obtaining knowledge ofthe DRX behaviour for each mobile device. The DRX controller 29 may bepart of a base station and may be implemented in software running onappropriate hardware, hardware, firmware or combinations thereof.

The wireless network 28 has components such as base stations (not shown)for providing wireless access. The scheduler 32 may reside in the basestations or elsewhere in the network 28. In LTE, the scheduler istypically in the eNB (enhanced NodeB). In the examples that follow, itis assumed scheduler 32 is part of a base station.

In the illustrated example, the scheduler 32 and radio manager 14 areimplemented as software and executed on processors forming part of thenetwork 28 and mobile device 10 respectively. However, more generally,these functions may be implemented as software, hardware, firmware, orany appropriate combination thereof.

Furthermore, it is to be understood that the wireless network would haveany appropriate components suitable for a wireless network 28. Note thatthe wireless network may include wires that interconnect networkcomponents in addition to components for providing wirelesscommunication with mobile devices. The components of the wirelessnetwork are implementation specific and may depend on the type ofwireless network. There are many possibilities for the wireless network.The wireless network might for example be a UMTS network or any cellularnetwork that uses semi-persistent resource assignment.

In operation, the mobile device 10 communicates with the wirelessnetwork 28 over a wireless connection 19 between the mobile device 10and the wireless network 28. The communication with the wireless network28 includes VoIP packet transmission and additional packet transmission.The semi-persistent scheduler 34 is responsible for making an initialresource allocation for a VoIP service to the mobile device 10. Thisincludes an uplink semi-persistent allocation and a downlinksemi-persistent allocation. The semi-persistent scheduler 34 is alsoresponsible for keeping track of whether there is a talk-spurt inprogress for the uplink and/or the downlink and for turning on and offthe uplink and/or downlink allocation accordingly. While de-allocated,the semi-persistently allocated resources can be made available forother purposes. Note that the form of the transmission resources thatare being allocated is implementation specific. Particular examples ofresources that might be used include OFDM resources and CDMA resources.The dynamic scheduler 36 is responsible for making resource allocationsfor additional packet transmissions that are not accommodated by thesemi-persistent allocation. The additional packets may be related toand/or form part of the VoIP service, or be unrelated to the VoIPservice.

The radio manager 14 controls the on/off state of the wireless accessradio 12. In some wireless access radios, the transmitter and receivermust be turned on and off together, and as such, uplink and downlinkscheduling must be coordinated to allow the wireless access radio to beturned off. In some wireless access radios, receive and transmitcapabilities can be independently turned off.

In some embodiments, the network 28 sends DRX control signalling to themobile device 10 that sets a repeating pattern that has a DRX periodhaving an awake period and a sleep period. An example could be: DRXperiod is 20 ms with sleep period equal to 15 ms and awake period equalto 5 ms. During the awake period, the mobile device turns its receiveron. During the sleep period, the mobile device turns its receiver off.This signalling might be sent at the start of each VoIP session, forexample.

In some embodiments, in addition to the above-discussed DRX controlfunctions, the DRX controller 29 performs radio resource control andradio resource management, which take care of one or more of radioresource assignment/release/re-assignment, radio bearer control,admission control, radio related signalling, mobility, measurement, andpaging, to name a few specific examples.

Referring now to FIG. 3, shown is a signalling diagram showing anexample of semi-persistent and dynamic scheduling and DRX. Shown is asemi-persistent allocation 60 available for semi-persistent VoIPdownlink transmissions. In addition, there are layer 1 CCEs 62 forsignalling dynamic allocations so as to allow the transmission ofadditional packets. This represents the transmissions from the basestation. The mobile device receiving the transmissions alternatesbetween being in an awake state and a sleep state. The mobile station isin an awake state during awake periods 64 and the mobile device isnominally in a sleep state during sleep periods 66. The first thing thatthe scheduler in the network needs to do is to ensure that thesemi-persistent allocation 60 coincides with the awake periods 64. Inaddition, each awake period 64 is longer than the minimum necessary totransmit the VoIP semi-persistent allocation. There is also theopportunity to dynamically schedule (as signalled on one of the CCEs 62)and transmit an additional packet. An example of this is shown where adynamic allocation is signalled in CCE 62-1. Additional packet 67 isshown transmitted immediately following CCE 62-1. The additional packetmight for example be an RTCP packet, SIP/SDP packet, or a packet thathas not undergone IP\UDP\RTP header compression, etc. While the mobiledevice is in the sleep state, it operates in a reduced power consumptionmode, by turning off reception capability and/or by turning off itsreception and transmission capabilities. In this example, the networkhas scheduled the additional packet 67 to be transmitted during one ofthe awake periods 64, and signals this using a CCE 62-1 that istransmitted during one of the awake periods 64. More generally, when themobile device wakes up after a sleep period, the mobile device will notonly blind detect its own VoIP data on the semi-persistently allocatedresource 60, but also will detect, more generally attempt to detect, allthe CCEs during the awake periods.

In some embodiments, after the mobile device determines that there willbe a dynamically allocated resource for the mobile device as signalledin one of the CCEs in a given awake period, the mobile device does notmonitor further CCEs during that awake period.

In some embodiments, the base station will transmit signalling toconfigure the mobile device with this DRX behaviour, and thereafter allthe dynamic scheduling will occur only in this “awake period”. Forexample, the mobile device may sleep every 15 ms, and then wake up for 5ms to continuously receive data. The behaviour repeats with a period of20 ms. During the 5 ms awake period, the mobile device will blind-detectits VoIP data on the semi-persistently allocated resource and also themobile device will monitor all the CCEs. The base station understandsthis DRX configuration and will schedule the associated dynamic packetssuch as RTCP, SIP/SDP, etc, during this 5 ms awake period. In someimplementations, when a retransmission occurs, the mobile device will bein continuous mode by default.

The radio manager 14 controls the operation of the wireless access radio12 such that a reception capability is powered on during the awakeperiods, and off for at least some of the sleep periods. As describedbelow, it may be necessary for the reception capability to be on duringsome of the sleep periods to allow for retransmissions.

The signalling for dynamic scheduling is performed during the awakeperiods. In addition, the actual resources allocated for the additionalpacket transmissions are scheduled to occur during the awake periods.

In some embodiments, when it becomes necessary for a retransmission, themobile device enters a continuous mode of operation. While in continuousmode, the mobile device continuously receives and monitors the downlinkchannel and does not turn off reception capability. Further, in someembodiments, if a mixed service needs to be provided to the mobiledevice, this is used as a trigger to also enable the continuous modeoperation. This trigger may be dependent on the traffic QoS of theservice being added.

Uplink Semi-Persistent Alignment with Downlink for DRX

The above discussion is focussed on downlink transmission from the basestation to the mobile device and on the mobile device's ability to turnoff its reception capability during the sleep period. However, somemobile devices are not able to turn off only their reception capabilitywhile leaving on a transmit capability or vice versa. Thus, for suchdevices in order to fully realize the benefit of having an awake periodand a sleep period for reception, uplink transmissions should also bescheduled to align with these awake periods and sleep periods. Anexample of this is shown in FIG. 4. In FIG. 4, the downlink transmissionis indicated at 78 and this is basically the same as that describedabove with reference to FIG. 3, and this will not be described again.The uplink transmissions are generally indicated at 80. Here, there is asemi-persistent allocation 82 for VoIP UL transmissions. These arescheduled to occur during the periods 64 that the mobile device isawake. In addition, an uplink control channel is indicated at 84. In theillustrated example, this occurs every 1 ms. The mobile device onlytransmits the uplink control channel during the awake periods 64. Themobile device can use the uplink control channel to make requests foradditional resources. By scheduling the uplink semi-persistenttransmission and downlink semi-persistent transmission to occur duringthe same awake period, the mobile device can realize much more efficientDRX and DTX (discontinuous reception and discontinuous transmission)behaviour. In the example of FIG. 4, the mobile device is configured tosleep every 15 ms, and then wake up for 5 ms. During this 5 ms awakeperiod, the mobile device will receive DL semi-persistent reception ifavailable (during a DL talk-spurt) and make an uplink semi-persistenttransmission if available (during an UL talk-spurt). The mobile devicewill also detect all the DL grants and possibly make uplink additionalresource requests.

In case of retransmissions (either the DL or the UL), the mobile devicewill enter the continuous mode by default. Note that both the uplink anddownlink VoIP semi-persistent allocations have the same trafficcharacteristics (every 20 ms), hence the base station can easily alignthe semi-persistent allocation for the DL and UL.

With this approach, even in the active mode (talk-spurt in progress onthe uplink or the downlink), the mobile device can be in DRX and DTXmode most of the time. The mobile device monitors the Layer 1 CCEs onthe downlink only during the awake period, and may request moreresources on the uplink. This can save battery power for the mobiledevice. Considering that an additional IP packet delivery during a VoIPsession may be infrequent, the battery saving could be significant. Adrawback is that the dynamic scheduling could be delayed by anadditional 10 ms on average.

Referring now to FIG. 5, shown is a state diagram having DRX/DTX statetransitions for VoIP. It is noted that when there is no uplink anddownlink transmission (i.e. silence in both directions), the mobiledevice only needs to monitor the DL CCEs for dynamic scheduling duringthe awake period. There are two main states. The first main state is theUE sleep state 100 and the second main state is the UE awake state 102.For the illustrated example, it is assumed that the sleep state 100lasts 15 ms and the awake state lasts 5 ms and can be extended, but thisis again implementation specific. Blocks 102-1 and 102-2 illustrateactions executed by the UE for downlink communication during the awakestate 102. At block 102-1, the UE receives all of the downlink CCEs andprocesses them to identify downlink dynamic scheduling if present. Thisis done irrespective of whether or not there is any downlink VoIPtransmission. In the event that a downlink talk-spurt is ongoing, thenthe UE, at block 102-2 receives the VoIP payload in the semi-persistentresource. Blocks 102-3 and 102-4 illustrate actions executed by the UEin respect of uplink transmissions. At block 102-3, the UE makes aresource request over a random access channel (RACH) and monitors thedownlink CCE for uplink grants, if the mobile device determines that itneeds a dynamic allocation for uplink transmission. In addition, ifthere is an uplink talk-spurt in progress, then the mobile device, atblock 102-4, transmits the uplink VoIP payload in the semi-persistentresource for uplink transmission.

The above description has focussed on applications where the trafficthat is sent using the semi-persistent allocation is VoIP traffic. Moregenerally, the same methods and systems can be applied to combine thetransmission and scheduling of traffic of any type on asemi-persistently allocated resource with the transmission andscheduling of traffic that uses dynamic resource allocations.

In the above examples, CCEs spaced by 1 ms are used for the downlinkcontrol channel. More generally, the downlink control channel can takeany form. The only limitation is that dynamic allocations for a givenmobile device take place during awake periods for the mobile device.Similarly, at least in the figures, the uplink control channel has beendepicted as a random access channel that is available at intervalsspaced by 1 ms. More generally, the uplink control channel forrequesting additional resource allocations can come in any form. Theonly limitation is that requests for dynamic allocations for uplinktransmission from a given mobile device will need to be transmittedduring awake periods for the mobile device.

In some embodiments, the additional packet is transmitted as a series ofone or more sub-packets formed by segmenting the additional packet.These are subject to reassembly at the receiver.

Methods for Semi-Persistent Scheduling and DRX Control Executed by theWireless Network

A method in a wireless network for performing downlink transmission tomobile devices will be described with reference to the flowchart of FIG.6. This method is performed for each mobile device being providedwireless access on a semi-persistent downlink transmission resource. Themethod begins at block 6-1 with transmitting downlink packets to themobile device using a semi-persistent downlink transmission resourcethat is aligned with awake periods defined for the mobile device. Thesecan be downlink VoIP packets during a downlink talk-spurt for a VoIPsession involving the mobile device or otherwise. Blocks 6-2,6-3,6-4 areexecuted for each additional downlink packet for the mobile device. Inblock 6-2, the wireless network dynamically allocates an additionaldownlink transmission resource to transmit the additional packet, theadditional resource being allocated to occur within one of the awakeperiods defined for the mobile device. In block 6-3, during one of theawake periods defined for the mobile device, the wireless networktransmits signaling that defines the additional downlink transmissionresource to transmit the additional packet. In block 6-4, during one ofthe awake periods defined for the mobile device, the wireless networktransmits the additional downlink packet using the additional downlinkresource. In some embodiments, this method is performed in a basestation. In other embodiments, certain portions of the method, forexample the dynamic allocation, can be performed in another networkelement if centralized scheduling is performed.

A method in a wireless network for performing uplink reception frommobile devices will be described with reference to the flowchart of FIG.7. This method is performed for each mobile device being providedwireless access on a semi-persistent downlink transmission resource. Themethod begins at block 7-1 with the wireless network receiving uplinkpackets from the mobile device using a semi-persistent uplinktransmission resource that is aligned with the awake periods defined forthe mobile device. These can be VoIP packets during an uplink talk-spurtfor a VoIP session involving the mobile device or otherwise. Blocks 7-2,7-3, 7-4 and 7-5 are performed for each additional each additionaluplink packet for the mobile device. In block 7-2, during one of theawake periods, the wireless network receives a request for an additionaluplink transmission resource to transmit the additional uplink packet.In block 7-3, the wireless network dynamically allocates the additionaluplink transmission resource such that the additional uplinktransmission resource occurs during one of the awake periods defined forthe mobile device. In block 7-4, during one of the awake periods definedfor the mobile device, the wireless network transmits signaling thatdefines the additional uplink allocation. In block 7-5, the wirelessnetwork receives the additional uplink packet using the additionaluplink transmission resource.

In some embodiments, the wireless network transmits signaling to eachmobile device that defines the awake periods and that defines sleepperiods of that mobile device and/or that defines the semi-persistentuplink and/or downlink transmission resource of that mobile device. ForVoIP, the signaling to define the semi-persistent resources might bedone at the start of each VoIP session. Such signaling can be performedon a channel that is dedicated to each mobile device, or using abroadcast channel containing such signaling for multiple devices.

Methods for Semi-Persistent Scheduling and DRX Control Executed by theMobile Device

Referring now to FIG. 8, a method of receiving downlink transmissionexecuted by a mobile device will now be described. The method begins atblock 8-1 with the mobile device controlling a reception capability ofthe mobile device during a plurality of awake periods and a plurality ofsleep periods, the awake periods alternating in time with the sleepperiods, such that the reception capability is always on during each ofthe awake periods, and the reception capability is off for at least someof the sleep periods. On a nominal basis, typically the receptioncapability will be off for every sleep period. At block 8-2, the mobiledevice receives downlink packets on a semi-persistent downlinktransmission resource that is aligned with a plurality of awake periodsdefined for the mobile device. These can be VoIP downlink packets duringa downlink talk-spurt for a VoIP session involving the mobile device, orotherwise. Blocks 8-3 and 8-4 are performed for each additional downlinkpacket for the mobile device. In block 8-3, during one of the awakeperiods, the mobile device receives signaling that defines an additionaldownlink transmission resource to transmit the additional packet, theadditional downlink transmission resource being allocated to occurwithin one of the awake periods defined for the mobile device. In block8-4, during one of the awake periods, the mobile device receives theadditional downlink packet on the additional downlink resource.

The mobile device may receive signaling that defines the awake periodsand the sleep periods of the mobile device and/or that defines thesemi-persistent downlink transmission resource of that mobile device.This may take place over a respective dedicated channel for the mobiledevice or over a broadcast channel containing signaling information forthe mobile device and other mobile devices.

Referring now to FIG. 9, a method of transmitting uplink transmissionsexecuted by a mobile device will now be described. The method begins atblock 9-1 with controlling a transmission capability of the mobiledevice such that the transmission capability is on during all of theawake periods and such that the transmission capability is off for atleast some of the sleep periods. In block 9-2, the mobile devicetransmits uplink packets (VoIP packets or otherwise) using asemi-persistent uplink transmission resource that is aligned with theawake periods defined for the mobile device. Blocks 9-3, 9-4, 9-5 areexecuted for each additional uplink packet for the mobile device. Inblock 9-3, during one of the awake periods defined for the mobiledevice, the mobile device transmits a request for an additional uplinktransmission resource to transmit the additional uplink packet. In block9-4, during one of the awake periods, the mobile device receivessignaling that defines the additional uplink transmission resource, theadditional uplink transmission resource being allocated to occur duringone of the awake periods defined for the mobile device. In block 9-5,during one of the awake periods, the mobile device transmits theadditional uplink packet using the additional uplink transmissionresource.

The mobile device may receive signaling that defines the semi-persistentuplink resource. In some embodiments, the request for an additionaluplink allocation is transmitted using a contention based random accesschannel.

In some embodiments, mobile devices have radios that feature atransmitter and a receiver. While the radio is on, the receivercapability is on, and the receiver will be actively attempting toprocess signals received on the mobile device's antenna(s). There is notnecessarily content for the given mobile device all the time that thereceiver is on, but the receiver is consuming power nonetheless for thattime period. In addition, while the radio is on, the mobile device isable to transmit. However, so long as the mobile device does not havesomething to transmit, there is no active transmission taking place, andas such little or no transmit power consumption occurs until there is anactive transmission.

In embodiments referring to NACK/ACK transmission, the particularNACK/ACK scheme employed is implementation specific. Some embodimentsemploy an ACK only scheme; other embodiments employ a NACK only scheme,while others use both ACKs and NACKs.

Extensions to Periods for Further Dynamic Allocations

In some embodiments, as described in the detailed examples above, thedynamic allocations are always scheduled to occur during one of theawake periods that are nominally defined with fixed duration. In anotherembodiment, an awake period can be extended to allow for thetransmission/reception of one or more dynamic allocations. For example,a CCE sent during an awake period can allocate a dynamic resourceallocation, and the mobile device stays powered on to allow that. Duringthe period that the mobile device is powered on as a result of thedynamic resource allocation the mobile device continues to monitor theCCEs, and an additional CCE signalling another dynamic allocation can besent and so on.

Referring now to FIG. 11, shown is a flowchart of a method for executionon a mobile device, such as the mobile device 10 of FIG. 2 for example.

The method starts at block 11-1 with the mobile device controlling itsradio during a plurality of awake periods and a plurality of sleepperiods, the awake periods alternating in time with the sleep periods,such that the radio is always on during each of the awake periods, andthe radio is off for at least some of the sleep periods. Examples of howthis might be achieved have been described above. The awake periods arealso referred to as on periods, or periods of nominal on duration.

At block 11-2, the mobile device receives downlink packets on asemi-persistent downlink transmission resource that is aligned with theplurality of awake periods defined for the mobile device. In the eventthere is something to send during a given awake period, it is sent onthe semi-persistent downlink transmission resource. If there is nothingto send, the semi-persistent resource is not used. Various examples havebeen provided above.

Blocks 11-3, 11-4 and 11-5 are performed for an additional downlinkpacket or sub-packet for the mobile device. To begin, at block 11-3,during one of the awake periods, the mobile device receives signalingthat defines an additional transmission resource to communicate theadditional packet or sub-packet. The receipt of such signalling is atrigger for the mobile device to control its radio to be on for anadditional period at block 11-4. The additional period occurs during aportion of a sleep period. At block 11-5, during the portion of thesleep period that the mobile device is keeping its radio on, the mobiledevice monitors for signaling that defines yet another additionaltransmission resource to another additional packet or sub-packet. In theevent such signaling is received, yes path at block 11-6, the mobiledevice keeps its radio on for an additional portion of the sleep periodat block 11-7 and the method continues back at block 11-5. In the eventno such signalling is received (no path, block 11-6) typically, themobile device will turn its radio off at the end of the additionalperiod. This is shown at block 11-8. It is possible the mobile devicewill keeps its radio on for some other reason.

The use of an inactivity timer is one mechanism for realizing thefunctionality described above with reference to FIG. 11. In someembodiments, upon receiving signalling that defines the additionaltransmission resource to transmit the additional packet or sub-packet,the mobile device starts a timer that counts down the additional period.The timer may be referred to as an inactivity timer because the mobiledevice will turn its radio off only if the timer times out without anyactivity (i.e. further dynamic allocation). If before the expiry of thetimer signalling is received that defines yet another additionaldownlink transmission, the mobile device restarts the timer. The mobiledevice keeps is radio on as long as the timer has not expired. So longas the timer has not expired, additional dynamic allocations can be madethat will restart the timer. The mobile device monitors for signalingdefining further transmission resources to transmit further additionalpackets or sub-packets so long as the timer has not expired. In someembodiments, the timer starts when signaling that defines the additionaltransmission resource is received. In some embodiments, the timer startswhen the packet transmitted on the resource thus allocated iscommunicated to/by the mobile device.

The methods described above may, for example, be implemented by theradio manager 14 in controlling the wireless access radio 12 of FIG. 2.The control functionality may be implemented in hardware, software,firmware, or any combination thereof. Another embodiment provides acomputer readable medium having instructions stored thereon forexecution by a mobile device that control the execution of one of themethods described above.

Referring now to FIG. 12, shown is a flowchart of a method for executionby a wireless network. This might, for example, be executed by thewireless network 28 of FIG. 2. Typically the method would be executed bya base station that is providing wireless access to a given mobiledevice, but other network components may be involved as well. Varioussteps are executed for each mobile device of a plurality of mobiledevices. At block 12-1, the network transmits downlink packets to themobile device using a semi-persistent downlink transmission resourcethat is aligned with awake periods defined for the mobile device. Themobile device will have its radio on during these periods and will beable to receive the transmission. In the event there is nothing for themobile device during a given awake period, the semi-persistent resourceis not used to transmit to the mobile device for that period. Blocks12-2, 12-3 and 12-4 are executed for each additional packet orsub-packet for the mobile device. At block 12-2, the network dynamicallyallocates an additional transmission resource to communicate theadditional packet or sub-packet. At block 12-3, during one of the awakeperiods defined for the mobile device, the network transmits signalingthat defines the additional transmission resource to communicate theadditional packet or sub-packet, the signaling indicating to the mobiledevice to keep its radio on for a portion of a sleep period. At block12-4, the network communicates the additional downlink packet using theadditional downlink resource. At block 12-5, the network optionallytransmits signaling defining an additional dynamic allocation in theevent there is yet another additional packet or sub-packet for themobile device. Before the mobile device conditionally turns off itsradio at the end of the additional period, the network transmitssignalling defining an additional dynamic allocation, the signallingindicating the mobile device to keep its radio on for yet anotherportion of the sleep period.

The methods described above may, for example, be implemented by thescheduler 32 of the wireless network 28 of FIG. 2. The controlfunctionality may be implemented in hardware, software, firmware, or anycombination thereof. Another embodiment provides a computer readablemedium having instructions stored thereon for execution by a wirelessnetwork that control the execution of one of the methods describedabove.

More generally, in some embodiments, the mobile device keeps its radioon for an additional period beyond the normal awake period for anynumber of reasons. Specific examples include transmission of anACK/NACK, reception of a retransmission in the event the packet wasreceived in error, and receiving a dynamically scheduled transmission.If during such an additional period the mobile device receives a dynamicallocation, the mobile device starts a timer upon receipt of adynamically scheduled transmission during which the radio is kept on. Inaddition, the mobile device re-starts the timer upon receipt of afurther dynamically scheduled transmission before expiry of the timer.

In some embodiments, the portion of the sleep period is an extension ofan awake period. In other embodiments, the portion of the sleep periodis separate and distinct from the awake periods.

In some embodiments, this behavior is implemented in respect of dynamicallocations for uplink transmission in which case the transmissionresource is an uplink transmission resource, and the communication onthe additional transmission resource involves transmission from themobile device to the network. In other embodiments, this behavior isimplemented in respect of dynamic allocations for downlink transmissionI which case the transmission resource is a downlink transmissionresource, and the communication on the additional transmission resourceinvolves transmission from the network to the mobile device. In otherembodiments, this behavior is implemented in respect of dynamicallocations for uplink or downlink transmission in which case theadditional transmission resource may be either an uplink transmissionresource or a downlink transmission resource, and the communication onthe additional transmission resource may involve transmission from themobile device to the network, or from the network to the mobile device.In the detailed examples that follow it is assumed that the dynamicallocations are for downlink transmission.

Another Mobile Device

Referring now to FIG. 10, shown is a block diagram of another mobiledevice that may implement any of the mobile device methods describedherein. The mobile device 101 is shown with specific components forimplementing features similar to those of the mobile device 10 of FIG.2. It is to be understood that the mobile device 101 is shown with veryspecific details for example purposes only.

A processing device (a microprocessor 128) is shown schematically ascoupled between a keyboard 114 and a display 126. The microprocessor 128may be a specific example of the processor with features similar tothose of the processor 16 of the mobile device 10 shown in FIG. 2. Themicroprocessor 128 controls operation of the display 126, as well asoverall operation of the mobile device 101, in response to actuation ofkeys on the keyboard 114 by a user.

The mobile device 101 has a housing that may be elongated vertically, ormay take on other sizes and shapes (including clamshell housingstructures). The keyboard 114 may include a mode selection key, or otherhardware or software for switching between text entry and telephonyentry.

In addition to the microprocessor 128, other parts of the mobile device101 are shown schematically. These include: a communications subsystem170; a short-range communications subsystem 103; the keyboard 114 andthe display 126, along with other input/output devices including a setof LEDs 104, a set of auxiliary I/O devices 106, a serial port 108, aspeaker 111 and a microphone 112; as well as memory devices including aflash memory 116 and a Random Access Memory (RAM) 118; and various otherdevice subsystems 120. The mobile device 101 may have a battery 121 topower the active elements of the mobile device 101. The mobile device101 is in some embodiments a two-way radio frequency (RF) communicationdevice having voice and data communication capabilities. In addition,the mobile device 101 in some embodiments has the capability tocommunicate with other computer systems via the Internet.

Operating system software executed by the microprocessor 128 is in someembodiments stored in a persistent store, such as the flash memory 116,but may be stored in other types of memory devices, such as a read onlymemory (ROM) or similar storage element. In addition, system software,specific device applications, or parts thereof, may be temporarilyloaded into a volatile store, such as the RAM 118. Communication signalsreceived by the mobile device 101 may also be stored to the RAM 118.

The microprocessor 128, in addition to its operating system functions,enables execution of software applications on the mobile device 101. Apredetermined set of software applications that control basic deviceoperations, such as a voice communications module 130A and a datacommunications module 130B, may be installed on the mobile device 101during manufacture. In addition, a personal information manager (PIM)application module 130C may also be installed on the mobile device 101during manufacture. The PIM application is in some embodiments capableof organizing and managing data items, such as e-mail, calendar events,voice mails, appointments, and task items. The PIM application is alsoin some embodiments capable of sending and receiving data items via awireless network 110. In some embodiments, the data items managed by thePIM application are seamlessly integrated, synchronized and updated viathe wireless network 110 with the device user's corresponding data itemsstored or associated with a host computer system. As well, additionalsoftware modules, illustrated as another software module 130N, may beinstalled during manufacture. One or more of the modules130A,130B,130C,130N of the flash memory 116 can be configured forimplementing features similar to those of the radio manager 14 of themobile device 10 shown in FIG. 2.

Communication functions, including data and voice communications, areperformed through the communication subsystem 170, and possibly throughthe short-range communications subsystem 103. The communicationsubsystem 170 includes a receiver 150, a transmitter 152 and one or moreantennas, illustrated as a receive antenna 154 and a transmit antenna156. In addition, the communication subsystem 170 also includes aprocessing module, such as a digital signal processor (DSP) 158, andlocal oscillators (LOs) 160. The communication subsystem 170 having thetransmitter 152 and the receiver 150 is an implementation of a specificexample of the wireless access radio 12 of the mobile device 10 shown inFIG. 2. The specific design and implementation of the communicationsubsystem 170 is dependent upon the communication network in which themobile device 101 is intended to operate. For example, the communicationsubsystem 170 of the mobile device 101 may be designed to operate withthe Mobitex™, DataTAC™ or General Packet Radio Service (GPRS) mobiledata communication networks and also designed to operate with any of avariety of voice communication networks, such as Advanced Mobile PhoneService (AMPS), Time Division Multiple Access (TDMA), Code DivisionMultiple Access (CDMA), Personal Communications Service (PCS), GlobalSystem for Mobile Communications (GSM), etc. The communication subsystem170 may also be designed to operate with an 802.11 Wi-Fi network, and/oran 802.16 WiMAX network. Other types of data and voice networks, bothseparate and integrated, may also be utilized with the mobile device101.

Network access may vary depending upon the type of communication system.For example, in the Mobitex™ and DataTAC™ networks, mobile devices areregistered on the network using a unique Personal Identification Number(PIN) associated with each device. In GPRS networks, however, networkaccess is typically associated with a subscriber or user of a device. AGPRS device therefore typically has a subscriber identity module,commonly referred to as a Subscriber Identity Module (SIM) card, inorder to operate on a GPRS network.

When network registration or activation procedures have been completed,the mobile device 101 may send and receive communication signals overthe communication network 110. Signals received from the communicationnetwork 110 by the receive antenna 154 are routed to the receiver 150,which provides for signal amplification, frequency down conversion,filtering, channel selection, etc., and may also provide analog todigital conversion. Analog-to-digital conversion of the received signalallows the DSP 158 to perform more complex communication functions, suchas demodulation and decoding. In a similar manner, signals to betransmitted to the network 110 are processed (e.g., modulated andencoded) by the DSP 158 and are then provided to the transmitter 152 fordigital to analog conversion, frequency up conversion, filtering,amplification and transmission to the communication network 110 (ornetworks) via the transmit antenna 156.

In addition to processing communication signals, the DSP 158 providesfor control of the receiver 150 and the transmitter 152. For example,gains applied to communication signals in the receiver 150 and thetransmitter 152 may be adaptively controlled through automatic gaincontrol algorithms implemented in the DSP 158.

In a data communication mode, a received signal, such as a text messageor web page download, is processed by the communication subsystem 170and is input to the microprocessor 128. The received signal is thenfurther processed by the microprocessor 128 for an output to the display126, or alternatively to some other auxiliary I/O devices 106. A deviceuser may also compose data items, such as e-mail messages, using thekeyboard 114 and/or some other auxiliary I/O device 106, such as atouchpad, a rocker switch, a thumb-wheel, or some other type of inputdevice. The composed data items may then be transmitted over thecommunication network 110 via the communication subsystem 170.

In a voice communication mode, overall operation of the device issubstantially similar to the data communication mode, except thatreceived signals are output to a speaker 111, and signals fortransmission are generated by a microphone 112. Alternative voice oraudio I/O subsystems, such as a voice message recording subsystem, mayalso be implemented on the mobile device 101. In addition, the display126 may also be utilized in voice communication mode, for example, todisplay the identity of a calling party, the duration of a voice call,or other voice call related information.

The short-range communications subsystem 103 enables communicationbetween the mobile device 101 and other proximate systems or devices,which need not necessarily be similar devices. For example, theshort-range communications subsystem may include an infrared device andassociated circuits and components, or a Bluetooth™ communication moduleto provide for communication with similarly-enabled systems and devices.

Numerous modifications and variations of the present application arepossible in light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the applicationmay be practised otherwise than as specifically described herein.

1. A method in a wireless device, the method comprising: configuring thedevice for discontinuous reception (DRX) having on durations; receivingsignalling over a control channel, during one of the on durations; andstarting an inactivity timer.
 2. The method of claim 1, furthercomprising: during a duration of the inactivity timer, controlling thedevice to an on duration; monitoring for downlink transmissions duringthe on duration; restarting the timer upon receiving the downlinktransmissions; and controlling the device to a low power mode at theexpiry of the timer.
 3. The method of claim 1, wherein the signalingover the control channel is an uplink grant.
 4. The method of claim 1,wherein the signaling over the control channel is a downlink grant. 5.The method of claim 1, further comprising restarting the inactivitytimer upon reception of an additional transmission.
 6. A wireless devicecomprising: a processor configured to control a receiver to have ondurations; a receiver configured to receive signalling over a controlchannel during one of the on durations; and the processor furtherconfigured to start an inactivity timer upon reception of the signallingover the control channel.
 7. The device of claim 6, wherein theprocessor is further configured: to control the receiver to be on duringa duration of the inactivity timer; to restart the inactivity timer uponreception of a downlink transmission; and to control the receiver to beoff at an expiry of the timer.
 8. The device of claim 6, wherein theprocessor is further configured to restart the inactivity timer uponreception of an additional transmission.
 9. A method of controlling aradio in a wireless device, the method comprising: controlling the radioduring a plurality of awake periods and a plurality of sleep periods,the awake periods alternating in time with the sleep periods, such thatthe radio is always on during each of the awake periods, and the radiois off for at least some of the sleep periods; receiving, during one ofthe awake periods, signaling that defines a downlink transmissionresource to communicate a packet or sub-packet, the transmissionresource allocated during a portion of a sleep period; controlling theradio to be on during the portion of the sleep period; and monitoring,during the portion of the sleep period, for signaling that defines anadditional transmission resource to communicate an additional downlinkpacket or sub-packet, and in the event such signaling is received,controlling the radio to be on for an additional portion of a sleepperiod.
 10. The method of claim 9, further comprising: starting a timerthat counts down the portion of the sleep period upon receivingsignalling that defines the downlink transmission resource to transmitthe additional downlink packet or sub-packet; and controlling the radioto be on as long as the timer has not expired.
 11. The method of claim10 further comprising: during any portion of a sleep period that themobile device is controlling the radio to be on, monitoring forsignaling defining further downlink transmission resources to transmitfurther additional packets or sub-packets so long as the timer has notexpired, and restarting the timer upon receiving such signaling or uponreceiving such a further additional packet or sub-packet; andcontrolling the radio to be off at the expiry of the timer.
 12. Awireless device comprising: a wireless access radio for sending andreceiving wireless communications to and from a network; a radio managerthat controls the radio of the wireless device during a plurality ofawake periods and a plurality of sleep periods, the awake periodsalternating in time with the sleep periods, such that the radio isalways on during each of the awake periods, and the radio is off for atleast some of the sleep periods; the wireless device further configuredto: receive, during one of the awake periods, signaling that defines adownlink transmission resource to transmit an additional downlink packetor sub-packet, the downlink transmission resource allocated during aportion of a sleep period; control the radio to be on during the portionof the sleep period; and monitor, during the portion of the sleepperiod, for signalling that defines additional downlink transmissionresource to transmit another additional downlink packet or sub-packet,and in the event such signalling is received, controlling the radio tobe on for an additional portion of a sleep period.
 13. The wirelessdevice of claim 12 further configured to: start a timer that counts downthe portion of the sleep period upon receiving signalling that definesthe additional downlink transmission resource to transmit the additionaldownlink packet or sub-packet or upon receiving the additional downlinkpacket or sub-packet; and control the radio to be on as long as thetimer has not expired.
 14. The wireless device of claim 12 furtherconfigured to: during any portion of a sleep period that the mobiledevice is controlling the radio to be on, monitor for signaling definingfurther downlink transmission resources to transmit further additionalpackets or sub-packets so long as the timer has not expired, andrestarting the timer upon receiving such signaling or upon receivingsuch a further additional packet or sub-packet; control the radio to beoff at the expiry of the timer.